Computer Control of Power Systems and Energy Management Systems

1. Computer Control of Power Systemsand Energy Management Systems

2. Outline • Introduction • Conceptual Model of the EMS • EMS Functions and SCADA Applications. • Time decomposition of the power system operation. • Open Distributed system in EMS • OOPS

3. EMS • Enhance the scope of SCADA by providing the power application software to assist the operator in monitoring and controlof the electrical network. • It consists of three important phases: • Gathering Information: Acquisition of real-time data and man machine information. • Decision Making. • Action by Transmitting Control Orders either • - Directly [Centralized Remote Control] • - Indirectly [Decentralized remote control or load • control].

4. Conceptual Model of EMS Fig 1. Typical EMS Architecture

5. Real Time Modeling of the system • Network Configuration Analysis • Observability Analysis • State Estimation and Data processing • Network Application Functions

6. EMS Application and SCADA Functions 1. Real-Time Functions ·         Topological Analysis ·         State Estimation ·         Network Equivalent Calculation ·         Security Analysis ·         Generation Dispatch ·         Voltage and Reactive Optimization 2. Extended Real-Time Functions ·         Short term Load Forecast ·         Operator Load Flow ·         Short Circuit Calculation

7. Online and Off line Tasks in an EMS

8. The Functions in the EMS can be classified as 1. Primary Analysis (Perform decision making tasks) Programs for Message Switching. Control of Information Display Systems. Recording of Status and events. Information Processing for telecommand and control 2. Secondary Analysis(Operational planning tasks)          State Estimation Optimal Power flow Network Security Analysis Load Prediction

9. Time Decomposition Of Power System Operation

10. Application Functions in Pre-Dispatch, Dispatch and Post-Dispatch modes of an EMS.

11. Hierarchical Control in EMS • Load frequency Control. • Economic Dispatch. • Power Exchange with Interconnected utilities. • Unit commitment. • Maintenance Scheduling

12. On line and Off line Functions

13. Application Programs in an Energy Control Centre

14. Operating States of Power system

15. No Operating State E: Equality Constraint I: Inequality Constraint 1 Normal 2 Alert 3 Emergency 4 In-Extremis 5 Restorative Description of the Operating states

16. No Operating State From To 1 Preventive Alert Normal 2 Preventive Emergency Through Alert Normal 3 Corrective Emergency Normal Different Types of Control Action

17. Framework for computer aids for decision making in control centers.

18. Applications for Energy Management Systems and Energy trading Systems

19. Block Diagram of an Integrated EMS

20. Open Distributed Systems • Closed System vs. Open System • Closed system software • Restricted to run on a proprietary platform. • Data sharing with other computers extremely difficult. • Open System software • No longer relied on the single vendor to supply all the hardware and software for the EMS • Select the each individual subsystem within the EMS from • different vendors

21. Impact of Open Systems in EMS • Purchase the hardware and software requirements for the • sufficient capacity only • - Incrementally upgrade the system as and when required. • - This helps in reducing the financial burden on the utilities • to change from the closed system to the open system.

22. Object Oriented Programming Advantages: 1. Reusability 2. Expandability 3. Portability • Encapsulation (Data Hiding) • 2. Polymorphism (Over Loading) • 3. Inheritance (Specialization) Features of OOPS:

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